diff --git a/src/nix/path-info.cc b/src/nix/path-info.cc
index 23198a120..080d6bbf1 100644
--- a/src/nix/path-info.cc
+++ b/src/nix/path-info.cc
@@ -54,7 +54,7 @@ static json pathInfoToJSON(
 
                 jsonObject["closureSize"] = getStoreObjectsTotalSize(store, closure);
 
-                if (auto * narInfo = dynamic_cast<const NarInfo *>(&*info)) {
+                if (dynamic_cast<const NarInfo *>(&*info)) {
                     uint64_t totalDownloadSize = 0;
                     for (auto & p : closure) {
                         auto depInfo = store.queryPathInfo(p);